JP5227853B2 - Oscillating gear device, transmission ratio variable mechanism, and vehicle steering device - Google Patents

Description

  The present invention relates to an oscillating gear device, a transmission ratio variable mechanism, and a vehicle steering device.

An oscillating gear device including a gear that performs oscillating motion has been proposed (see, for example, Patent Documents 1, 2, and 3). In Patent Document 1, the oscillating gear device is applied to a vehicle steering device including a transmission ratio variable mechanism that can change the steering angle ratio. In Patent Documents 2 and 3, a rocking gear device is applied to a transmission.
The oscillating gear device includes first and fourth gears opposed to each other, and an oscillating gear disposed between the first and fourth gears and inclined with respect to the first and fourth gears. ing. The swing gear includes a second gear that meshes with the first gear, and a third gear that meshes with the fourth gear. More specifically, the meshing between the first gear and the second gear is the meshing between a pin provided on the first gear and a tooth groove provided on the second gear.

JP 2006-82718 A JP 2005-351384 A JP 2006-46405 A

By the way, in a vehicle steering apparatus, suppression of generation of vibration and noise is demanded. Similarly, transmissions are required to suppress the generation of vibration and noise.
Accordingly, an object of the present invention is to provide a rocking gear device, a transmission ratio variable mechanism, and a vehicle steering device that can suppress the generation of vibration and noise.

The inventor of the present application has a three-dimensional rocking motion of the pins constituting the teeth, and the amount of rocking motion around the axis parallel to the central axis of the pin is the three-dimensional rocking motion. It has been found that if it is large, the vibration when the pin enters and exits the tooth gap increases, causing noise.
Therefore, the inventor of the present application has come up with the idea of suppressing the generation of vibrations and noises by optimizing the specifications of the pair of gears so that the amount of the above-described swing motion of the pin can be suppressed. As a result, the present invention has been completed.

The oscillating gear device (78, 88, 89) of the first invention has a center axis (Z31, Z34) on the first axis (Z1) and is rotatable around the center axis. It has a center axis (Z32, Z33) on the gears (211 and 214) and a second axis (Z2) that swings in an inclined state with respect to the first axis, and can rotate around the center axis A center axis oscillating gear (212, 213), and one of the shaft fixed gear and one of the axis oscillating gears (211, 214) is a side surface (70, 73) a plurality of holding grooves (79, 109) arranged radially about the central axis of the one gear and pins (77, 77) held in the holding grooves and constituting the teeth of the one gear. 87), and the pin includes the shaft fixed gear and the shaft center swing. The side surfaces (71, 72) of the other gear (212, 213) of the gears mesh with the tooth grooves (80, 110) arranged radially about the central axis of the other gear, The pin and the tooth groove engaged with each other are engaged in an engagement region (J11) having a predetermined length with respect to the longitudinal direction (X5) of the pin, and the central axis (J1) of the pin is the engagement region. Includes a facing region (J11) facing the radial direction (R5) of the pin, and the distance between an arbitrary point (P2) on the central axis of the pin in the facing region and the first axis is r _CO , the distance between the arbitrary point and the second axis is r _FO , the number of the pins of the first gear is Z _C, and the number of the tooth grooves of the second gear is Z _F The following equation (1): r _CO / r _FO = Z _C / Z _F (1) (Claim 1).

According to a second aspect, in the first aspect, a pair of the shaft center fixed gears (211 and 214) is provided, and each of the pair of shaft center fixed gears is a pair of side surfaces (71 , 72) is meshed with a corresponding side surface (claim 2).
A transmission ratio variable mechanism (5) of the third invention is a transmission ratio variable mechanism using the oscillating gear device of the present invention, and is provided with one of the pair of shaft fixed gears (211). A member (20), an output member (22) provided with the other (214) of the pair of shaft fixed gears, and a shaft rocking gear provided to allow differential rotation of the input member and the output member And an electric motor (23) for driving the intermediate member, and the transmission ratio from the input member to the output member is variable (claim 3). .

The vehicle steering device (1) according to the fourth aspect of the present invention is the ratio of the turning angle of the steered wheels (4L, 4R) to the steering angle of the steering member (2) using the transmission ratio variable mechanism (5) of the present invention. A vehicle steering apparatus capable of changing a certain transmission ratio, wherein the input member is connected to the steering member, and the output member is connected to a steered wheel side member (12). 4).
In addition, although the alphanumeric characters in the parentheses indicate reference signs of corresponding components in the embodiments described later, the scope of the claims is not limited by these reference signs.

According to the first aspect of the present invention, when the one gear and the other gear are engaged with each other and rotated, the three-dimensional rocking motion of the pin swings around an axis parallel to the center axis of the pin. Since the amount of dynamic motion is reduced, the vibration when the pin enters and exits the tooth gap is reduced. As a result, it is possible to suppress the vibration and noise of the oscillating gear device.
Note that the distance r _CO in the equation (1) may be an actual measurement value or a calculation value obtained by calculation using the actual measurement value or the target value. The same applies to the distance _rFO . From the distance r _CO and the distance r _FO , the r ratio (r ratio = r _CO / r _FO ) on the left side of the equation (1) is calculated, and the calculated r ratio should coincide with the tooth number ratio. At this time, it can be said that Formula (1) is materialized.

For example, referring to the schematic diagram of FIG. 8, the angle between the first axis Z1 and the second axis Z2 is λ, and the first axis Z1 is related to the direction in which the first axis Z1 extends. and the distance between the intersection P1 and the arbitrary point P2 of the second axis Z2 and a _RC, in the direction in which the second axis extends, a distance between the intersection P1 and the arbitrary point P2 and a _RF Then, the following equations (2) and (3) are established.
A _RF = A _RC × cos λ−r _CO × sin λ (2)
r _FO = r _CO × cos λ−A _RC × sin λ (3)
As specifications (target value or measured value) of the oscillating gear device, an angle λ, a distance r _CO , and a distance A _RF (or a distance A _RC ) may be given. At this time, the distance r _FO can be obtained by using the equations (2) and (3) and the given specifications, that is, the angle λ, the distance r _CO , and the distance A _RF (or the distance A _RC ). Furthermore, the r ratio of the left side of the equation (1) can be obtained.

According to the second invention, vibration and noise can be suppressed in the oscillating gear device having two pairs of the shaft center fixed gear and the shaft center oscillating gear.
According to the third invention, the ratio of the rotation angle of the output member to the rotation angle of the input member can be changed by driving the intermediate member by the electric motor.
According to the fourth aspect, by making the transmission ratio variable, the turning angle of the steered wheels with respect to the steering of the steering member can be optimized according to the traveling state of the vehicle. For example, when the vehicle is stopped or running at low speed, such as when entering a garage, by increasing the transmission ratio, the turning amount of the steered wheels can be increased relative to the steering amount. The amount can be reduced. Further, when the vehicle is traveling on a snowy road or the like, so-called active steering can be performed in which the counter steer operation is automatically performed by the transmission ratio variable mechanism.

It is a mimetic diagram showing a schematic structure of a steering device for vehicles provided with a transmission ratio variable mechanism concerning one embodiment of the present invention. It is sectional drawing which shows the more concrete structure of the principal part of FIG. FIG. 3 is an enlarged view of a transmission ratio variable mechanism in FIG. 2 and its surroundings. It is an enlarged view of the principal part of the transmission ratio variable mechanism of FIG. It is a perspective view of the principal part of a 1st rocking | fluctuation type gear apparatus. It is sectional drawing of the principal part which follows the VI-VI line of FIG. It is a side view of a 1st rocking | fluctuation type gear apparatus. It is a schematic diagram of a 1st rocking | fluctuation type gear apparatus. It is a graph which shows the locus | trajectory of relative movement of a pin and a tooth space, (a) shows the case where Formula (1) is not materialized, (b) shows the case where Formula (1) is materialized. The horizontal axes of (a) and (b) indicate the relative movement amount of the pin with respect to the tooth groove in the rotation direction of the gear. The vertical axis | shaft of (a), (b) shows the relative movement amount of the pin with respect to the tooth gap regarding the depth direction of a tooth gap. FIG. 10 is a schematic diagram of the second gear for explaining the mathematical expression. FIG. 11 is an explanatory view of the movement of the pin of the second gear of FIG.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the present embodiment, a description will be given based on the case where the oscillating gear device is applied to a transmission ratio variable mechanism of a vehicle steering device. The oscillating gear device of the present invention can also be used for applications other than the transmission ratio variable mechanism of the vehicle steering device.
FIG. 1 is a schematic diagram of a schematic configuration of a vehicle steering apparatus to which an oscillating gear device according to an embodiment of the present invention is applied. Referring to FIG. 1, a vehicle steering apparatus 1 applies a steering torque applied to a steering member 2 such as a steering wheel to left and right steered wheels 4L and 4R via a steering shaft 3 as a steering shaft. The steering is given. The vehicle steering apparatus 1 has a VGR (Variable Gear Ratio) function capable of changing the transmission ratio θ2 / θ1 as the ratio of the steered wheel turning angle θ2 to the steering angle θ1 of the steering member 2.

The vehicle steering apparatus 1 includes a steering member 2 and a steering shaft 3 connected to the steering member 2. The steering shaft 3 includes first, second and third shafts 11, 12, 13 arranged coaxially with each other. The central axes of the first to third axes 11 to 13 are also rotation axes of the first to third axes 11 to 13.
The steering member 2 is connected to one end of the first shaft 11 so as to be able to rotate together. The other end of the first shaft 11 and one end of the second shaft 12 are connected via the transmission ratio variable mechanism 5 so as to be differentially rotatable. The second shaft 12 and the third shaft 13 are coupled via a torsion bar 14 so as to be elastically rotatable relative to each other within a predetermined range and transmit power.

The third shaft 13 is connected to the steered wheels 4L and 4R via the universal joint 7, the intermediate shaft 8, the universal joint 9, the steering mechanism 10, and the like.
The steered mechanism 10 includes a pinion shaft 15 connected to the universal joint 9, and a rack shaft 16 as a steered shaft that has a rack 16a that meshes with the pinion 15a at the tip of the pinion shaft 15 and extends in the left-right direction of the vehicle. Yes. Knuckle arms 18L and 18R are connected to the pair of ends of the rack shaft 16 via tie rods 17L and 17R, respectively.

  With the above-described configuration, the rotation of the steering member 2 is transmitted to the steering mechanism 10 via the steering shaft 3 and the like. In the turning mechanism 10, the rotation of the pinion 15 a is converted into the axial movement of the rack shaft 16. The axial movement of the rack shaft 16 is transmitted to the corresponding knuckle arms 18L and 18R via the tie rods 17L and 17R, and the knuckle arms 18L and 18R rotate. Accordingly, the corresponding steered wheels 4L and 4R connected to the knuckle arms 18L and 18R are respectively steered.

  The transmission ratio variable mechanism 5 is for changing the rotation transmission ratio (transmission ratio θ2 / θ1) between the first and second shafts 11 and 12 of the steering shaft 3, and is a nutation gear mechanism. . The transmission ratio variable mechanism 5 includes an input member 20 provided at the other end of the first shaft 11, an output member 22 provided at one end of the second shaft 12, and the input member 20 and the output member 22. And a bearing ring unit 39 as an intermediate member interposed therebetween.

The input member 20 is connected to the steering member 2 and the first shaft 11 so that torque can be transmitted. The output member 22 is connected to the second shaft 12 as a steered wheel side member so that torque can be transmitted. The output member 22 is connected to the steered wheels 4L and 4R via the second shaft 12, the steered mechanism 10, and the like.
The input member 20 is supported rotatably around the central axis of the input member 20. The output member 22 is supported so as to be rotatable around the central axis of the output member 22. The central axis of the input member 20 and the central axis of the output member 22 coincide with the first axis Z1.

The above-described track ring unit 39 includes an inner ring 391 as a first track ring, an outer ring 392 as a second track ring, and rolling elements 393 such as balls interposed between the inner ring 391 and the outer ring 392. Constitutes a ball bearing.
As the rolling element 393, a cylindrical roller, a needle roller, and a tapered roller can be used besides a ball. Further, the rolling elements 393 may be arranged in a single row, or may be arranged in a double row. The double row is suitable for preventing the inner ring 391 from falling over the outer ring 392. A double row angular bearing can be illustrated as a double row thing.

  The inner ring 391 connects the input member 20 and the output member 22 so as to be differentially rotatable. The inner ring 391 and the outer ring 392 have a common central axis that is inclined with respect to the first axis Z1. The inner ring 391 can rotate around the central axis of the inner ring 391. The central axis line of the inner ring 391 coincides with the second axis line Z2. The second axis Z2 is inclined at a predetermined inclination angle with respect to the first axis Z1, and swings in a state inclined with respect to the first axis Z1, as will be described later. Yes.

  The inner ring 391 is rotatable about the second axis Z2 by being rotatably supported by the outer ring 392 via the rolling elements 393. Further, the inner ring 391 can rotate around the first axis Z1 when the transmission ratio variable mechanism motor 23 which is an electric motor as an actuator for driving the outer ring 392 is driven. The inner ring 391 and the outer ring 392 can perform Coriolis motion (swing motion) around the first axis Z1.

The transmission ratio variable mechanism motor 23 is disposed radially outward of the race ring unit 39. The central axis of the transmission ratio variable mechanism motor 23 coincides with the first axis Z1. The transmission ratio variable mechanism motor 23 changes the transmission ratio θ2 / θ1 by changing the rotation speed of the outer ring 392 around the first axis Z1.
The transmission ratio variable mechanism motor 23 is composed of, for example, a brushless motor, and includes a rotor 231 that holds an outer ring 392 of the raceway ring unit 39 and a stator 232 that surrounds the rotor 231 and is fixed to a housing 24 as a steering column. It is out. The rotor 231 rotates around the first axis Z1.

  The vehicle steering apparatus 1 includes a steering assist force applying mechanism 19 for applying a steering assist force to the steering shaft 3. The steering assist force applying mechanism 19 includes the above-described second shaft 12 as an input shaft continuous with the output member 22 of the transmission ratio variable mechanism 5 and the above-described third shaft 13 as an output shaft continuous with the steering mechanism 10. A torque sensor 44 (described later) for detecting torque transmitted between the second shaft 12 and the third shaft 13, a steering assist motor 25 as a steering assist actuator, and a steering assist motor 25; A speed reduction mechanism 26 interposed between the third shaft 13 and the third shaft 13 is included.

The steering assist motor 25 is an electric motor such as a brushless motor. The output of the steering assist motor 25 is transmitted to the third shaft 13 via the speed reduction mechanism 26.
The speed reduction mechanism 26 is composed of, for example, a worm gear mechanism. The speed reduction mechanism 26 is a worm shaft 27 serving as a drive gear coupled to the output shaft 25a of the steering assist motor 25, and a driven gear coupled to the worm shaft 27 and coupled to the third shaft 13 so as to be able to rotate together. And a worm wheel 28. The speed reduction mechanism 26 is not limited to the worm gear mechanism, and other gear mechanisms such as a parallel shaft gear mechanism may be used. The parallel shaft gear mechanism described above includes, for example, a pair of spur gears that mesh with each other, and a helical gear may be used instead of the spur gear.

The transmission ratio variable mechanism 5 and the steering assist force applying mechanism 19 are arranged in the housing 24. The housing 24 is disposed in a passenger compartment (cabin) of the vehicle. The housing 24 may be disposed so as to surround the intermediate shaft 8 or may be disposed in the engine room of the vehicle.
Driving of the transmission ratio variable mechanism motor 23 and the steering assist motor 25 is controlled by a control unit 29 including a CPU, a RAM, and a ROM, respectively. The control unit 29 is connected to the transmission ratio variable mechanism motor 23 via the drive circuit 40, and is connected to the steering assist motor 25 via the drive circuit 41.

The control unit 29 includes a steering angle sensor 42, a rotation angle detection sensor 43 including a motor resolver for detecting the rotation angle of the transmission ratio variable mechanism motor 23, a torque sensor 44 as a torque detection means, and a turning angle sensor 45. A vehicle speed sensor 46 and a yaw rate sensor 47 are connected to each other.
A signal about the rotation angle of the first shaft 11 is input from the steering angle sensor 42 to the control unit 29 as a value corresponding to the steering angle θ1 that is the operation amount from the straight position of the steering member 2.

A signal regarding the rotation angle θr of the rotor 231 of the transmission ratio variable mechanism motor 23 is input from the rotation angle detection sensor 43 to the control unit 29.
From the torque sensor 44, a signal regarding the torque acting between the second and third shafts 12 and 13 is input as a value corresponding to the steering torque T acting on the steering member 2.

A signal about the rotation angle of the third shaft 13 is input from the turning angle sensor 45 to the control unit 29 as a value corresponding to the turning angle θ2.
A signal regarding the vehicle speed V is input from the vehicle speed sensor 46 to the control unit 29.
A signal regarding the yaw rate γ of the vehicle is input from the yaw rate sensor 47 to the control unit 29.

The control unit 29 controls driving of the transmission ratio variable mechanism motor 23 and the steering assist motor 25 based on the signals of the sensors 42 to 47 described above.
With the above configuration, the output of the transmission ratio variable mechanism 5 is transmitted to the steering mechanism 10 via the steering assist force applying mechanism 19. More specifically, the steering torque input to the steering member 2 is input to the input member 20 of the transmission ratio variable mechanism 5 via the first shaft 11, and the first of the steering assist force applying mechanism 19 is output from the output member 22. Is transmitted to the second shaft 12.

The steering torque transmitted to the second shaft 12 is transmitted to the torsion bar 14 and the third shaft 13, and together with the output from the steering assist motor 25, is transmitted to the steering mechanism 10 via the intermediate shaft 8 or the like. The
FIG. 2 is a cross-sectional view showing a more specific configuration of the main part of FIG. Referring to FIG. 2, the housing 24 is formed by forming a metal such as an aluminum alloy into a cylindrical shape, and includes a first housing 51, a second housing 52, and a third housing 53. It is out. In the housing 24, a first bearing 31, a second bearing 32, a third bearing 33, a fourth bearing 34, a fifth bearing 35, a sixth bearing 36, and a seventh bearing 37 (simplified) Is shown). For example, each of the first to seventh bearings 31 to 37 is a rolling bearing. More specifically, the first to fifth bearings 31 to 35 and the seventh bearing 37 are angular ball bearings. The sixth bearing 36 is a needle roller bearing.

  The first housing 51 has a cylindrical shape, constitutes a differential mechanism housing that houses the transmission ratio variable mechanism 5 as a differential mechanism, and a motor housing that houses the transmission ratio variable mechanism motor 23. It is composed. One end of the first housing 51 is covered with an end wall member 54. One end of the first housing 51 and the end wall member 54 are fixed to each other using a fastening member 55 such as a bolt. An annular convex portion 57 at one end of the second housing 52 is fitted to the inner peripheral surface 56 at the other end of the first housing 51. The first and second housings 51 and 52 are fixed to each other using a fastening member (not shown) such as a bolt.

The second housing 52 has a cylindrical shape, and constitutes a sensor housing that houses the torque sensor 44 and a resolver housing that houses the rotation angle detection sensor 43. The inner peripheral surface 60 at one end of the third housing 53 is fitted to the outer peripheral surface 59 at the other end of the second housing 52.
The third housing 53 has a cylindrical shape and constitutes a speed reduction mechanism housing that houses the speed reduction mechanism 26. An end wall portion 61 is provided at the other end of the third housing 53. The end wall portion 61 has an annular shape. The end wall portion 61 closes the other end of the third housing 53.

FIG. 3 is an enlarged view of the transmission ratio variable mechanism 5 of FIG. 2 and its surroundings. Referring to FIG. 3, the input member 20, the output member 22 of the transmission ratio variable mechanism 5, and the inner ring 391 of the raceway ring unit 39 each have an annular shape.
The input member 20 and the inner ring 391 are connected to each other by a first gear 211 and a second gear 212 that mesh with each other so that power can be transmitted. The inner ring 391 and the output member 22 are connected to each other by a third gear 213 and a fourth gear 214 that mesh with each other so as to transmit power.

The input member 20 has a first gear 211. The first gear 211 includes an input member main body 201 as a gear main body, a plurality of pins 77 held by the input member main body 201, an inner holder 75 for holding the plurality of pins 77 on the input member main body 201, and And an outer retainer 76.
The input member 20 includes a cylindrical member 202 that is disposed radially inward of the input member main body 201 and can rotate along with the input member main body 201. The input member main body 201 and the cylindrical member 202 are integrally formed using a single material.

The other end of the first shaft 11 is inserted through the insertion hole 202 a of the cylindrical member 202. The other end of the first shaft 11 serving as the input shaft of the transmission ratio variable mechanism 5 and the cylindrical member 202 are connected so as to be able to transmit torque, for example, by serration engagement.
The output member 22 has a fourth gear 214. The fourth gear 214 includes an output member main body 221 as a gear main body, a plurality of pins 87 held by the output member main body 221, an inner holder 85 for holding the plurality of pins 87 by the output member main body 221, and And an outer retainer 86.

The output member 22 includes a cylindrical member 222 that is disposed radially inward of the output member main body 221 and can rotate together with the output member main body 221. The output member main body 221 and the cylindrical member 222 are integrally formed using a single material.
One end of the second shaft 12 is inserted through the insertion hole 222 a of the cylindrical member 222 of the output member 22. The intermediate portion of the second shaft 12 as the output shaft of the transmission ratio variable mechanism 5 and the output member 22 are connected so as to be able to transmit torque, for example, by serration engagement.

  The inner ring 391 of the track ring unit 39 is integrally formed using a single member, and is disposed between the input member 20 and the output member 22. The inner ring 391 includes a second gear 212 that is paired with the first gear 211 of the input member 20 and a third gear 213 that is paired with the fourth gear 214 of the output member 22. The inner ring 391 has a first end 391a and a second end 391b in the axial direction of the inner ring 391. The first end 391 a is formed as a gear body of the second gear 212. The second end 391 b is formed as a gear body of the third gear 213. The first and second end portions 391a and 391b are aligned with each other, and can rotate together around the second axis Z2 as the matching axis.

The outer ring 392 is fixed in a press-fitted state in an inclined hole 63 formed in the inner periphery of the rotor 231 of the motor 23 for variable transmission ratio mechanism. The outer ring 392 rotates together with the rotor 231 around the first axis Z1. As the rotor 231 rotates around the first axis Z1, the bearing ring unit 39 performs Coriolis motion.
In the present embodiment, the description will be made in accordance with the raceway ring unit 39 configured as described above, but it may be configured as follows. That is, the outer ring 392 may connect the input member 20 and the output member 22 so as to be differentially rotatable, and the inner ring 391 may be connected to the rotor 231 of the transmission ratio variable mechanism motor 23 so as to be rotatable together. In this case, the race ring unit 39 is an inner ring support type. The second gear 212 and the third gear 213 are provided on the side surface of the outer ring 392 as an intermediate member.

FIG. 4 is an enlarged view of a main part of the transmission ratio variable mechanism 5 of FIG. Referring to FIG. 4, the center axis Z31 of the first gear 211 is coincident with the center axis of the input member 20 and also coincides with the first axis Z1. The first gear 211 is rotatable around the central axis Z31 of the first gear 211.
The center axis Z34 of the fourth gear 214 coincides with the center axis of the output member 22, and also coincides with the first axis Z1. The fourth gear 214 is rotatable around the central axis Z34 of the fourth gear 214.

The center axis Z32 of the second gear 212 coincides with the second axis Z2. The second gear 212 is rotatable around the central axis Z32 of the second gear 212.
The center axis Z33 of the third gear 213 coincides with the second axis Z2. The third gear 213 is rotatable around the central axis Z33 of the third gear 213.
The center axis Z32 of the second gear 212 and the center axis Z33 of the third gear 213 are rotated around the first axis Z1 while being inclined with respect to the first axis Z1. . Therefore, the second gear 212 and the third gear 213 are also referred to as axially oscillating gears.

On the other hand, the central axis Z31 of the first gear 211 and the central axis Z34 of the fourth gear 214 are neither rotated nor displaced. Therefore, the first gear 211 and the fourth gear 214 are also referred to as axial center fixed gears.
The first oscillating gear device 78 is configured by the first gear 211 and the second gear 212 that meshes with the first gear 211 so that power can be transmitted. Further, a second oscillating gear device 88 is constituted by the third gear 213 and the fourth gear 214 that meshes with the third gear 213 so that power can be transmitted. The first oscillating gear device 78 and the second oscillating gear device 88 form a third oscillating gear device 89.

The input member 20 and the output member 22 of the third oscillating gear device 89 have the same center axis, and are arranged with the first end portion 391a and the second end portion 391b of the inner ring 391 interposed therebetween. ing.
The first gear 211 has a side surface 70. The side surface 70 is provided at the end of the input member 20 in the axial direction. The fourth gear 214 has a side surface 73. The side surface 73 is provided at the axial end of the output member 22.

  The inner ring 391 has a side surface 71 of the second gear 212 and a side surface 72 of the third gear 213. The side surface 71 of the second gear 212 and the side surface 72 of the third gear 213 are opposed to each other in the axial direction of the inner ring 391. A side surface 71 of the second gear 212 is formed as a part of the first end portion 391 a of the inner ring 391 and faces the side surface 70 of the first gear 211. The side surface 72 of the third gear 213 is formed as a part of the second end 391 b of the inner ring 391 and faces the side surface 73 of the fourth gear 214.

FIG. 5 is a perspective view of a main part of the first oscillating gear device 78. 4 and 5, the first gear 211 includes a plurality of holding grooves 79 formed on the side surface 70 of the first gear 211, and a plurality of pins 77 held in the holding grooves 79. have.
The second gear 212 includes a plurality of tooth grooves 80 formed on the side surface 71 of the second gear 212 and engaged with the corresponding pins 77. The tooth gap 80 and the pin 77 can be engaged with each other.

The holding grooves 79 and the pins 77 are arranged on the side surface 70 at equal intervals in the circumferential direction of the input member 20 over the entire area in the circumferential direction of the input member 20.
The tooth grooves 80 are arranged on the side surface 71 at equal intervals in the circumferential direction of the inner ring 391 over the entire area in the circumferential direction of the inner ring 391.
For example, 38 pieces of the holding grooves 79 and the pins 77 are arranged. The number of tooth gaps 80 is a number different from the number of pins 77, for example, 40 that is larger than the number of pins 77. Note that the number of teeth of the shaft fixed gear is smaller than the number of teeth of the shaft swing gear.

  Each pin 77 is for forming the teeth 81 of the first gear 211 and is, for example, a needle roller having a cylindrical shape. These pins 77 are arranged radially about the central axis Z31 of the first gear 211. Half of each pin 77 protrudes from the corresponding holding groove 79 and has a semicircular cross section. The protruding half is the tooth 81 of the first gear 211. Out of each pin 77, the outer end 77a of the first gear 211 in the radial direction R1 is collectively held by the annular outer cage 76, and the inner end 77b of the first gear 211 in the radial direction R1 is These are held together by an annular inner holder 75.

Each pin 77 is held in contact with the holding groove 79 of the input member main body 201 by the outer holder 76 and the inner holder 75. Each of the outer cage 76 and the inner cage 75 is formed of an elastic member, for example, a synthetic resin, and is attached to the input member main body 201.
Referring to FIG. 5, the holding groove 79 is radially elongated around the central axis Z31 of the first gear 211, and extends across the entire side surface 70 in the radial direction of the first gear 211. The first gear 211 is arranged at equal intervals in the circumferential direction. The number of holding grooves 79 is equal to the number of pins 77, and the pins 77 are held in the holding grooves 79. In FIG. 5, the inner holder 75 and the outer holder 76 are not shown.

  The tooth groove 80 is formed in an elongated shape radially about the central axis Z32 of the second gear 212, and extends over the entire side surface 71 in the radial direction of the second gear 212 (also the radial direction of the inner ring 391). And arranged at equal intervals in the circumferential direction of the second gear 212. The number of tooth spaces 80 is different from the number of pins 77. Depending on the difference between the number of pins 77 and the number of tooth gaps 80, a shift can be performed between the input member main body 201 and the inner ring 391.

Referring to FIG. 4 again, the second axis Z2 of the inner ring 391 is inclined by a predetermined angle λ with respect to the first axis Z1 of the input member 20, whereby a plurality of pins 77 of the first gear 211 are obtained. A part of the pins 77 and a part of the plurality of tooth grooves 80 of the second gear 212 mesh with each other.
6 is a cross-sectional view of a main part taken along line VI-VI in FIG. FIG. 6 shows a cross section orthogonal to the longitudinal direction of the pin 77 meshing with the tooth groove 80. Referring to FIGS. 5 and 6, the outer peripheral surface of pin 77 is formed of a cylindrical surface. The diameter of the outer peripheral surface of the pin 77 is constant with respect to the direction along the central axis J1 of the pin 77.

  The tooth groove 80 extends in the shape of a bowl having a concave curved cross section. In addition, in the cross section orthogonal to the central axis of the pin 77, the inner surface of the tooth groove 80 has, for example, a so-called gothic arc shape. The bottom 801 of the tooth gap 80 is sharpened. The bottom 801 of the tooth gap 80 and the pin 77 are not in contact with each other. Further, the cross-sectional shape of the tooth groove 80 has the same shape over the entire region of the tooth groove 80 in the longitudinal direction. The tooth groove 80 includes a pair of contact portions 802 arranged in the circumferential direction of the second gear 212 with the bottom 801 interposed therebetween. When the protruding end of the pin 77 reaches the innermost part of the tooth gap 80, the pair of contact portions 802 and the outer peripheral surface of the pin 77 can come into contact with each other. Each contact portion 802 is formed by an arc surface. The radius of curvature of the arc surface is larger than the radius of the outer peripheral surface of the pin 77.

  Referring to FIG. 4, the third gear 213 is configured in the same manner as the second gear 212 except for the following points. The fourth gear 214 is configured in the same manner as the first gear 211 except for the following points. That is, the fourth gear 214 is provided on the output member 22. The third gear 213 is provided at the second end 319 b of the inner ring 391. Further, the difference in the number of teeth between the third gear 213 and the fourth gear 214 is different from the difference in the number of teeth between the first gear 211 and the second gear 212. For example, in the present embodiment, the difference in the number of teeth between the first gear 211 and the second gear 212 is larger than the difference in the number of teeth between the third gear 213 and the fourth gear 214, but conversely It is also possible to do.

Further, the side surface 72 of the third gear 213 has a plurality of tooth spaces 110. The tooth gap 110 is formed in the same manner as the tooth gap 80 described above.
The side surface 73 of the fourth gear 214 has a plurality of holding grooves 109, a plurality of pins 87, and an inner holder 85 and an outer holder 86 for holding the pins 87. The holding groove 109 is configured in the same manner as the holding groove 79 of the first gear 211. The pin 87 is configured in the same manner as the pin 77 of the first gear 211. The inner cage 85 and the outer cage 86 are configured in the same manner as the inner cage 75 and the outer cage 76.

  The meshing state of the third gear 213 and the fourth gear 214 is the same as the meshing state of the first gear 212 and the second gear 212. Although a detailed description of the third gear 213 and the fourth gear 214 is omitted, the third gear 213 and the fourth gear 214 can also be obtained from the relationship between the first gear 212 and the second gear 212. Effects can be obtained. Below, it demonstrates according to the relationship between the 1st gearwheel 212 and the 2nd gearwheel 212. FIG.

Referring to FIG. 3, the rotor 231 of the transmission ratio variable mechanism motor 23 includes a cylindrical rotor core 112 extending in the axial direction S.
In the present embodiment, the rotor core 112 that supports the outer ring 392 of the bearing ring unit 39 rotatably supports the cylindrical member 202 of the input member 20 via the first bearing 31, and via the third bearing 33. The cylindrical member 222 of the output member 22 is rotatably supported.

  Further, the outer ring of the first bearing 31 is positioned in the axial direction by the step portion of the rotor core 112. The outer ring of the third bearing 33 is positioned in the axial direction by the step portion of the rotor core 112. The outer ring 392 of the bearing ring unit 39 is positioned in the axial direction by the step portion of the rotor core 112. Thereby, the relative movement in the axial direction of the outer ring 392, the input member 20, and the output member 22 is restricted.

The rotor core 112 is supported at both ends by second and fourth bearings 32 and 34 that sandwich the first and third bearings 31 and 33 in the axial direction S.
The second bearing 32 is held by an annular convex portion 114 formed on the inner diameter portion of one end of the first housing 51. The fourth bearing 34 is held by an annular extending portion 115 formed at the inner diameter portion of the other end of the second housing 52.

The annular extending portion 115 has a cylindrical shape extending from the partition wall portion 116 provided at the other end of the second housing 52 to one side S1 in the axial direction S, and is inserted inward of the rotor core 112. .
FIG. 7 is a side view of the first oscillating gear device 78. Referring to FIG. 7, the plurality of pins 77 of the first gear 211 and the plurality of tooth grooves 80 of the second gear 212 are simultaneously engaged with each other. On the other hand, since there are a plurality of pairs of pins 77 and tooth grooves 80 that simultaneously engage with each other, interference between the pins 77 and the tooth grooves 80 is likely to occur. When this interference occurs, vibration and noise occur in the circumferential direction.

In the present embodiment, the first oscillating gear device 78 is configured so that a formula (1) described later is established so that the above-described interference can be suppressed.
Note that the second oscillating gear device 88 is also configured to satisfy the same expression (1). In the third oscillating gear device 89, it is preferable that the expression (1) is satisfied in both the first and second oscillating gear devices 78 and 88. Expression (1) may be established on one of the dynamic gear devices 78 and 88. In the following, description will be made in accordance with the first oscillating gear device 78.

FIG. 8 is a schematic diagram of the first oscillating gear device 78. Referring to FIG. 8, in the first oscillating gear device 78, the pin 77 and the tooth groove 80 meshing with each other are engaged in engagement regions 771 and 803 having a predetermined length X2 with respect to the longitudinal direction X5 of the pin 77. Match. The engagement region 771 is on the outer peripheral surface of the pin 77. The engagement region 803 is on the inner surface of the tooth gap 80.
The central axis J1 of the pin 77 includes a facing region J11 that faces the engaging regions 771, 803 in the radial direction R5 of the pin 77. The distance between the arbitrary point P2 on the central axis J1 of the pin 77 in the facing area J11 and the first axis Z1 is r _CO , the distance between the arbitrary point P2 and the second axis Z2 is r _FO , When the number of the pins 77 of the first gear 211 is Z _C and the number of the tooth grooves 80 of the second gear 212 is Z _F , the following formula (1): r _CO / r _FO = Z _C / Z _F …… (1) is established.

  According to the present embodiment, when the first gear 211 as one gear and the second gear 212 as the other gear are engaged with each other and rotated, Thus, since the amount of swinging motion around the axis parallel to the central axis J1 of the pin 77 is reduced, the vibration when the pin 77 enters and exits the tooth groove 80 is reduced. As a result, vibration and noise generation of the first oscillating gear device 78 can be suppressed.

The distance r _{CO in the} equation (1) may be an actual measurement value or a calculation value obtained by calculation using the actual measurement value or the target value. The same applies to the distance _rFO . From the distance r _CO and the distance r _FO , the r ratio (r ratio = r _CO / r _FO ) on the left side of the equation (1) is calculated, and the calculated r ratio should coincide with the tooth number ratio. At this time, it can be said that Formula (1) is materialized.
For example, an angle formed by the first axis Z1 and the second axis Z2 is λ, and an intersection point P1 between the first axis Z1 and the second axis Z2 and an arbitrary point P2 with respect to the direction in which the first axis Z1 extends. the distance between the a _RC, in the direction in which the second axis Z2 extends, a distance between the intersection P1 and the arbitrary point P2 is taken as a _RF, the following formula (2), (3) holds.
A _RF = A _RC × cos λ−r _CO × sin λ (2)
r _FO = r _CO × cos λ−A _RC × sin λ (3)
For example, as the specifications (target values or measured values) of the first and second gears 211 and 212 of the first oscillating gear device 78, the angle λ, the distance r _CO, and the distance A _RF (or the distance A _RC ). May be given. At this time, the distance r _FO can be obtained by using the equations (2) and (3) and the given specifications, that is, the angle λ, the distance r _CO , and the distance A _RF (or the distance A _RC ). Furthermore, the r ratio of the left side of the equation (1) can be obtained.

For example, the arbitrary point P2 described above is included in a plane P12 (see FIG. 6) including both the first axis Z1 and the second axis Z2. More specifically, the arbitrary point P2 described above is arranged at the center position of the facing region J11 on the central axis J1 of the pin 77. In this case, vibration can be effectively suppressed.
When the formula (1) is established, the pitch of the pin 77 of the first gear 211 when measured along a circle passing through the above-mentioned arbitrary point P2 and centering on the first axis Z1, The pitches of the tooth grooves 80 of the second gear 212 when measured along a circle passing through the arbitrary point P2 and centered on the second axis Z2 are equal to each other.

In other words, by setting the specifications (for example, the distance r _CO and the distance r _FO ) so that the expression (1) is established, the pitches of the teeth of the first gear 211 and the second gear 212 are equal to each other. This can be achieved reliably and easily. Therefore, the vibration and noise of the first oscillating gear device 78 can be reliably and easily reduced.
In the conventional oscillating gear device, the pitch of the teeth of the first and second gears has not been considered as important. As a result, for example, in the setting of the above-mentioned specifications, since the formula (1) is not established, the tooth pitches of the first and second gears are different from each other. As a result, the above-described vibration and noise were caused.

  It is also conceivable to adopt a pin or tooth groove shape that can suppress vibration. Since such a shape is complicated, it is difficult to process, and the manufacturing cost is high. On the other hand, in this embodiment, in order to suppress the occurrence of vibration, the specifications of the pair of gears are set to values that satisfy the above-described equation (1), so the shapes of the pin and the tooth gap are simplified. it can. Therefore, the manufacturing cost can be reduced. In addition, generation of vibration and noise can be suppressed.

Further, the effect obtained by the above-described expression (1) will be specifically described. That is, consider the relative movement of the specific pin 77 and the tooth groove 80 that mesh with each other. The locus of the relative movement of the pin 77 with respect to the tooth groove 80 when the formula (1) is established was obtained by the formula (4) described later. In addition, the locus of the relative movement of the pin with respect to the tooth gap when Equation (1) is not satisfied was similarly obtained.
FIG. 9 is a graph showing the calculation result of the relative movement trajectory between the pin and the tooth gap. FIG. 9A shows a conventional case where the expression (1) is not satisfied, and FIG. 9B is the expression where the expression (1) is satisfied. The case of this embodiment is shown. The horizontal axes of (a) and (b) indicate the relative movement amount of the pin with respect to the tooth groove in the rotation direction of the gear. The vertical axis | shaft of (a), (b) shows the relative displacement | movement amount of the pin with respect to the tooth space regarding the depth direction of a tooth space. The graphs (a) and (b) are obtained by calculating a point indicating the center position of the pin with respect to the tooth gap, and connecting the obtained points with a line. The center of the pin is at the bottom of the tooth gap. The center position of the pin when closest is indicated by a point G0.

According to the graphs of FIG. 9A and FIG. 9B, the pins 77 move relative to the depth direction of the tooth spaces 80 (corresponding to the vertical direction of the graph) when entering and exiting the corresponding tooth spaces 80. At the same time, the first gear 211 (or the second gear 212) may be moved relative to the rotation direction (corresponding to the horizontal direction in the graph).
When the formula (1) is satisfied (see FIG. 9B), the pin relative to the horizontal axis of the graph is compared with the case where the formula (1) is not satisfied (see FIG. 9A). The amount of movement is relatively small. That is, it can be said that the relative displacement amount between the pin 77 and the tooth groove 80 in the rotation direction is small.

9B, when the pin 77 is separated from the point G0 by a predetermined distance G4 in the depth direction of the tooth groove 80, the engagement between the pin 77 and the tooth groove 80 is released. become. There are two points G5 when this engagement is released. A distance G1 in the rotational direction between the two points G5 is obtained. Similarly, referring to FIG. 9A, the distance G2 in the rotational direction between the two points G5 is obtained.
As these distances G1 and G2 are larger, vibration in the rotational direction is more likely to occur between the pin and the tooth groove that mesh with each other. The distance G1 when Formula (1) is satisfied is smaller than the distance G2 when Formula (1) is not satisfied. Therefore, it can be said that vibration is difficult to occur.

  Equation (4), which will be described later, for obtaining the graphs of FIGS. 9A and 9B, the first gear 211 of the oscillating gear device has a tooth groove, and the second gear 212 is a pin. When the second gear 212 swings, the position of an arbitrary point of the pin is obtained. The position of the arbitrary point described above is given as the position of the point P5 obtained by moving the point P3 in FIG. 10 by the three rotational movements in FIG. In addition, when calculating | requiring the relative motion of the centers of a pin and a tooth space, a pin and a tooth space may exist in any gear.

FIG. 10 is a schematic diagram of the second gear for explaining an arbitrary point P3 of the pin of the second gear. FIG. 11 is an explanatory view of the movement of the pin of the second gear of FIG. FIG. 11 also shows a locus of an arbitrary point on the outer periphery of the pin when the second gear 212 swings, and an envelope of this locus (shown by a two-dot chain line).
Referring to FIG. 10, the second axis Z2 is along the Z axis of the coordinate axis. P3 is an arbitrary point of the pin of the second gear 212 and is illustrated on the outer peripheral surface of the pin. r _R is a variable for representing an arbitrary point P3, and is a distance between the arbitrary point P3 and the central axis J1 of the pin. When the arbitrary point P3 is on the outer peripheral surface of the pin, the distance r _R is equal to the radius of the outer peripheral surface of the pin. λ _R is an angle formed by the central axis J1 of the pin with respect to a plane orthogonal to the second axis Z2. Θ _R is a variable for representing an arbitrary point P3, and is an angle around the central axis J1 of the pin. d is a variable for representing an arbitrary point P3, and is the distance between the pin center P4 and the point P3 in the direction along the center axis J1 of the pin. r _F3 is the distance between the pin center P4 on the pin center axis J1 and the second axis Z2. B _RF is the distance between the intersection point P1 and the center P4 of the pin in the direction in which the second axis Z2 extends.

Referring to FIG. 11, the three rotational movements from arbitrary point P3 to point P5 are as follows: rotation about an angle −Φ about the Z axis, rotation about an angle λ about the X axis, and angle about the Z axis. Includes rotation at iΦ. The position P _{05 of the} point P5 is obtained by the following equation (4).
P ₀₅ = M ₁・ M ₂・ M ₃・ P ₀₃ …… (4)
here,
P ₀₃ = [X ₀ , Y ₀ , Z ₀ ]
X ₀ = r _R · sin θ _R
Y ₀ = d · cos λ _R + r _R · sin λ _R · cos θ _R + r _F3
Z ₀ = −d · sinλ _R + r _R · cosλ _R · cos θ _R + B _RF
P ₀₃ is the position of an arbitrary point P3 on the pin, X ₀ is the X coordinate of the point P3, Y ₀ is the Y coordinate of the point P3, and Z ₀ is the Z coordinate of the point P3. It is. M ₁ is a matrix for obtaining the position of a point when an arbitrary point is rotated around the Z axis at an angle −Φ, and is a function of Φ. M ₂ is a matrix for obtaining the position of a point when an arbitrary point is rotated around the X axis at an angle λ, and is a function of λ. M ₃ is a matrix for obtaining the position of a point when an arbitrary point is rotated around the Z axis at an angle iΦ, and is a function of iΦ.

Φ is the rotation angle of the swinging motion of the second gear 212. I is the ratio of the number of teeth. Here, the tooth number ratio i = Z _F / Z _C = (number of output teeth) / (number of input teeth). For example, the number of output teeth is the number of teeth of the second gear 212. The number of input teeth is the number of teeth of the first gear 211.
In equation (4), if r _R = 0 is set, Y = r _C0 is solved, and r _F3 = r _FO and r _CO / r _FO = Z _C / Z _F , the graph of FIG. 9B is obtained. It is done.

In equation (4), if r _R = 0 and Y = r _C0 is solved, r _F3 = r _FO , r _CO / r _FO = α · Z _C / Z _F (α> 1) The graph of FIG. 9A is obtained.
Referring to FIG. 4, in this embodiment, a pair of axially fixed gears, that is, first and fourth gears 211 and 214 are provided. Each of the pair of gears 211 and 214 is meshed with the corresponding side surfaces 71 and 72 of the inner ring 391 as an axial center oscillating gear. In this case, vibration and noise can be suppressed in the third oscillating gear device 89 having two pairs of axially fixed gears and axially oscillating gears.

  Further, the transmission ratio variable mechanism 5 of the present embodiment uses the third oscillating gear device 89 of the present embodiment. The input member 20 provided with the first gear 211 as one of the pair of shaft fixed gears, the output member 22 provided with the fourth gear 214 as the other of the pair of shaft fixed gears, and the shaft center Inner ring 391 as an intermediate member provided with second and third gears 212 and 213 as swinging gears and allowing differential rotation of input member 20 and output member 22, and variable transmission ratio for driving the intermediate member And an electric motor 23 for the mechanism. In this case, the ratio of the rotation angle of the output member 22 to the rotation angle of the input member 20 can be changed by driving the above-described intermediate member by the electric motor 23.

Referring to FIG. 1, the vehicle steering apparatus 1 according to the present embodiment uses a transmission ratio variable mechanism 5 to change a transmission ratio that is a ratio of the turning angles of the steered wheels 4 </ b> L and 4 </ b> R to the steering angle of the steering member 2. It is possible. The input member 20 is connected to the steering member 2, and the output member 22 is connected to the second shaft 12 as a steered wheel side member.
Thereby, by making the transmission ratio variable, the turning angle of the steered wheels with respect to the steering of the steering member 2 can be optimized according to the traveling state of the vehicle. For example, when the vehicle is stopped or running at low speed, such as when entering a garage, by increasing the transmission ratio, the turning amount of the steered wheels can be increased relative to the steering amount. The amount can be reduced. Further, when the vehicle is traveling on a snowy road or the like, so-called active steering can be performed in which the counter steer operation is automatically performed by the transmission ratio variable mechanism.

  With reference to FIGS. 1 and 2, the operation of the VGR function is as follows. When the rotor 231 of the transmission ratio variable mechanism motor 23 is rotating and the rotation of the input member 20 is restricted by the driver holding the steering member 2, the rotor 231 is the first. By rotating around the axis Z1, the ring unit 39 performs a so-called Coriolis motion. As a result, the inner ring 391 attempts to rotate the input member 20 and the output member 22 in the opposite directions. However, because the rotation of the input member 20 is restricted, only the output member 22 rotates.

  At this time, there is a first tooth number difference between the first gear 211 and the second gear 212, and there is a second tooth number difference between the third gear 213 and the fourth gear 214. The first tooth number difference and the second tooth number difference are different from each other. As a result, when the outer ring 392 of the track ring unit 39 rotates once, the inner ring 391 rotates by an amount corresponding to the first tooth number difference. Further, the output member 22 rotates by an amount corresponding to the second tooth number difference. As a result, the rotation of the rotor 231 of the transmission ratio variable mechanism motor 23 is decelerated and output.

  When the rotor 231 of the transmission ratio variable mechanism motor 23 is rotating and the input member 20 is rotating because the driver is steering the steering member 2, the rotation amount of the output member 22 is The rotation amount of the input member 20 (steering member 2) in the above-described case (when the rotation of the input member 20 is restricted by the rotation of the rotor 231 and the driver holding the steering member 2). It becomes the value which added.

Thus, when the vehicle is traveling at a relatively low speed, the function of assisting the driver's steering by amplifying the steering angle θ1 can be exhibited.
When the vehicle is traveling at a relatively high speed, for example, the behavior of the vehicle is determined by comparing the steering angle θ1 with the yaw rate γ of the vehicle. As a result, when the vehicle behavior determined from the steering angle θ1 does not match the vehicle behavior determined from the detected yaw rate γ, the rotation of the rotor 231 of the transmission ratio variable mechanism motor 23 is increased. The vehicle's stability control (posture stability control) is performed by decelerating or decelerating. At this time, the drive of the transmission ratio variable mechanism motor 23 can be controlled so that the counter steer operation is performed.

Moreover, the following modifications can be considered about this embodiment. In the following description, differences from the above-described embodiment will be mainly described. Although explanations of other configurations are omitted, they are the same as those in the above-described embodiment, and are given the same reference numerals.
For example, in the above-described embodiment, the case where the holding groove 79 and the pin 77 are provided in the first gear 211 of the input member 20 and the tooth groove 80 is provided in the second gear 212 of the inner ring 391 has been described. It is not limited. For example, the holding groove 79 and the pin 77 may be provided in the second gear 212 of the inner ring 391, and the tooth groove 80 may be provided in the first gear 211 of the input member 20. Similarly, the holding groove 109 and the pin 87 may be provided in the third gear 213 of the inner ring 391, and the tooth groove 110 may be provided in the fourth gear 214 of the output member 22.

  In short, one of the shaft center fixed gear and the shaft center oscillating gear has a plurality of holding grooves arranged radially on the side surface of the one gear and centered on the central axis of the one gear, And a pin that is held in each holding groove and constitutes the teeth of the one gear. If the pins mesh with the tooth grooves 80 radially arranged around the central axis of the other gear on the side surface of the other gear of the shaft fixed gear and the shaft swing gear Good.

  Although not shown, instead of the pin 77 and the tooth groove 80, a truncated cone-shaped pin and a tooth groove having a shape matching the shape of the pin may be used. The inner surface of the tooth groove is formed by a part of a conical surface, and can be in line contact or surface contact with the outer peripheral surface of the pin. Further, the diameter of the pin becomes smaller as it goes inward in the radial direction of the gear having the pin. Moreover, the case where the pin 77 and the holding groove 79 are integrally formed by a single member is also considered. The same applies to the pin 87 and the tooth gap 110.

In addition, when the number of teeth of the first gear 211 and the number of teeth of the second gear 212 are the same, the number of teeth of the third gear 213 and the number of teeth of the fourth gear 214 are the same. It is also conceivable that either one of the cases described above is adopted. In this case, the formula (1) can be applied to a pair of gears having different numbers of teeth.
Further, in each of the above-described embodiments, the transmission ratio variable mechanism 5 is applied to the steering shaft 3 as a steering shaft, but it may be applied to the intermediate shaft 8 and the pinion shaft 15 as the steering shaft. In these cases, the output member 22 is a steered wheel side member closer to the steered wheels 4L and 4R than the output member 22 in the transmission path through which the steering force is transmitted (for example, in the above-described embodiment, the second shaft 12).

  Further, the transmission ratio variable mechanism and the oscillating gear mechanism of the present invention can be applied to devices other than the vehicle steering device. For example, the transmission ratio variable mechanism and oscillating gear mechanism of the present invention can be applied to a toe angle variable mechanism that can vary a toe angle of a vehicle wheel, a camber angle variable mechanism that can vary a camber angle of a vehicle wheel, It can be applied to a damping force variable mechanism that can vary the damping force of the shock absorber. The transmission ratio variable mechanism and the oscillating gear mechanism according to the present invention are other general gear devices other than the vehicle steering device, and the gear device includes a pair of shaft fixed gears and a shaft oscillating gear. Applicable. In addition, various changes can be made within the scope of the matters described in the claims.

DESCRIPTION OF SYMBOLS 1 ... Steering device for vehicles, 2 ... Steering member, 4R, 4L ... Steering wheel, 5 ... Transmission ratio variable mechanism, 12 ... 2nd axis | shaft (steering wheel side member), 20 ... Input member, 22 ... Output member, 23 ... Transmission ratio variable mechanism motor (electric motor), 70 ... side surface of first gear, 71 ... side surface of second gear, 72 ... side surface of third gear, 73 ... side surface of fourth gear, 77, 87 ... pin, 78 ... first oscillating gear device, 79,109 ... holding groove, 80,110 ... tooth groove, 88 ... second oscillating gear device, 89 ... third oscillating gear device , 211... First gear (axially fixed gear, one gear), 212. Second gear (axially oscillating gear, other gear), 213... Third gear (axially oscillating gear, other gear) , 214 ... 4th gear (shaft fixed gear, one gear), 391 ... inner ring (intermediate member), 771, 803 ... engagement region, 1 ... pin center axis, J11 ... opposed region, P2 ... arbitrary point, R5 ... pin in the radial direction, r _CO ... distance between any point of the first axis, the r _FO ... arbitrary point and the second Distance from axis, X2 ... predetermined length, X5 ... longitudinal direction of pin, Z1 ... first axis, Z2 ... second axis, Z31 ... center axis of first gear, Z32 ... center of second gear Axis, Z33 ... center axis of the third gear, Z34 ... center axis of the fourth gear.

Claims (4)

An axially fixed gear having a central axis on the first axis and rotatable about the central axis;
An axially oscillating gear having a central axis on a second axis that oscillates in an inclined state with respect to the first axis, and rotatable about the central axis;
One of the shaft center fixed gear and the shaft center oscillating gear includes a plurality of holding grooves radially arranged around the central axis of the one gear on the side surface of the one gear, Each pin is held in a holding groove and constitutes a tooth of the one gear, and
The pins are engaged with tooth grooves radially arranged around the central axis of the other gear on the side surface of the other gear of the shaft fixed gear and the shaft swing gear.
The pin and the tooth groove engaged with each other are engaged in an engagement region having a predetermined length in the longitudinal direction of the pin,
The central axis of the pin includes a facing region facing the engaging region in the radial direction of the pin,
The distance between an arbitrary point on the central axis of the pin in the facing region and the first axis is r _CO ,
Let r _FO be the distance between the arbitrary point and the second axis,
Let Z _C be the number of pins of the first gear,
An oscillating gear device in which the following formula (1) is established when the number of the tooth grooves of the second gear is Z _F.
r _CO / r _FO = Z _C / Z _F (1)   2. The shaft fixed gear according to claim 1, wherein a pair of the shaft fixed gears are provided, and each of the pair of shaft fixed gears is meshed with a corresponding side surface of the pair of side surfaces of the shaft swing gear. An oscillating gear device.   A transmission ratio variable mechanism using the oscillating gear device according to claim 2, wherein an input member provided with one of the pair of shaft fixed gears and the other of the pair of shaft fixed gears are provided. An output member, an intermediate member that is provided with the shaft oscillating gear and allows differential rotation of the input member and the output member, and an electric motor for driving the intermediate member, and the input member A transmission ratio variable mechanism characterized in that the transmission ratio from the output to the output member is variable.   A vehicle steering apparatus capable of changing a transmission ratio, which is a ratio of a turning angle of a steered wheel to a steering angle of a steering member, using the transmission ratio variable mechanism according to claim 3, wherein the input member is the steering member. And the output member is connected to the steered wheel side member.

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